Hi Steve,
I can't help with a schematic for this set
(I'm in Australia) but as you are probably aware the
tube heaters are connected in series like Christmas
tree lamps. Their total voltage drop with a dial lamp
in series is about 78 to 80 volts. The extra 30 to 40
volts is dropped by the ballast tube. These are made
with a metal filament in a gas atmosphere (typically
iron fillament in hydrogen gas) which gives a high
resistance temperature coefficient which increases
with voltage to provide a constant current (0.3 Amp in
this case) even when the supply voltage varies. The
fixed resistors are probably causing too high a
starting current when the tube heaters are cold and
have a low resistance. I recomend you search the
various vintage spares suppliers and try to get the
correct ballast or a suitable substitute. Look at
http://www.antiqueradios.com/ballast.shtml for
extensive information and data on ballasts. A 110 volt
lamp of suitable current at 40 volts is better than a
fixed resistor as it has a large temperature coefficiet
but is a poor substitute for a proper ballast and I
strongly recomend you try for the correct one. It's a
lot cheaper than replacing burnt out tubes. I hope
this helps, if I can be of any further assistance
please just ask. Don.
Hi Steve
You need a ballast resistor of 150 ohms and at least 15 watts to drop 45 volts at .3 amps. Also be sure to put a resistor accross the dial light. Try a resistor around 22 ohms and adjust it until you have reasonable brightness. Due to the difference in turn on characteristics the dial light will surge bright when power is first applied. This is normal but you do not want the surge to the point where the light burns out. Radios with dial lights had two sections in the ballast tube, one being accross the light. Norm
: Hi Steve
: You need a ballast resistor of 150 ohms and at least 15 watts to drop 45 volts at .3 amps. Also be sure to put a resistor accross the dial light. Try a resistor around 22 ohms and adjust it until you have reasonable brightness. Due to the difference in turn on characteristics the dial light will surge bright when power is first applied. This is normal but you do not want the surge to the point where the light burns out. Radios with dial lights had two sections in the ballast tube, one being accross the light. Norm
Steve, your radio seems to be similar to GE H600, 601, 610 and 611 which is in Most Often Need 1940 Radio Diagrams. This schematic shows the same tube lineup including ballast. I'll mail you a copy if necessary.
Norm, thanks for the info. I would like a copy of the schematic. Leave an E-mail address for me to contact.
You can contact me at szmyslo@hotmail.com
I need number of part Q450
: I need number of part Q450